Percussive tool



I Dec. 21,1926( 1,611,227 E. PENBERTHY PERCUSSIVE TOOL I Fild May 25, '1925 IINVE/VTOR ERNEST PENBERTHY BYASATYOR/VEY I ERNEST ENBE THY, i on Darn-om, mrcnrean, nssrenon' TO emcsaq mavmm ,TOOL GOMPANLfQF New YORK, N; Y.-,j A oonronnrron OF NEW nsEY,

Application meanes; iezsn'sei-i rno; 32,270. J. I

7 n This invention "relates: .to "pressure tools of the percussive type. Whilethe in vention has features of gen-'eralutility it is V particularlyapplicable totools of the pojrtf able or hand supported type. V p w i One objectof the invention'is to provide an eflioientfand economical tool particularly adaptedjfor use with smallportableair com: pressors for road and contract worki An other object is to provide a percussive ,ma-i

chine which will operate well under varied conditions of fluid pressure such as obtain. 7 with the small portable operating units used on temporary j'obsvwhich' provide a1- limited V atively. low. pressures.

I which follows amount of motive fluid and frequently at relther'objects will be apparent from the detailed "-descriptlon The invention comprises a percussive tool in which the motive fluidis expansivelyused and its supply largely controlled by the pisa touch the rearward stroke of the latter and in which the motive fluid is noneexp'ansivelyused under control of a'valveon the forward p V 7 ton chamber and terminating at thefo'ther end-against the end; face of .valvehead 11*,

or work producing stroke of'the piston.

In order toillustrate the invention a preferred emhoclimentthereof is shown in the accompanying drawings in which :77 y Flg. 1 1s;a longitudinal sectional V1eW" 0' f the essentialparts of a drilling machine; and

Fig. 2 is a view similar to Fig. 1 but 'show- --ingr the mo'vablepart in a different position.

i 'jsThe. percussive machine disclosed comprises a' cylinder 3, prov1d1ng a; p1ston [chamber in which reciprocates a 'hammer piston 4 arrangedto deliverfblows toja work A i r her is open to exhaust through'port"i19., As

, 10 and 10". Branch 10 terminatesadjacenf f the head ll' ofa spool valve moiintedfor. reciprocatory movement "in a valve chamber tendsto' the rear end of "the pistonjchamherl' 12 in't-imed relation with piston 4. The "head 11 of the valve controls'anexhaust passage 7 '13 leading to atmosphere. Thefvalvehhas intermediate theheads 11 and 11 a' reduced portion or neck 11 and from th ef central portion of the valve chamber 12' there" eX-j a: passage 14 which isthus' in communication exhaust passage l 'dependent upon the por sition. of thevalve. From the .end face of head '11? of the valve" extends a passage 15 avhich comrhunio'ateswith thepiston chamher. in spaced relation to the rearward end =---'Branch 10' leads toward the front of the drill cylinder 3 terminating in a port 10 approximately rnidway offthe piston chamber,

the piston 4-is at or near theQfor ward limit spaced ports .16., and 17 Port 16"forms" a part of passage l'fi leading to and-controlled bythe head :11? of the valve. Port 17 forms terminating at'one end in a port 17? com municating with'the forward end of the pie- 'thereofso asto be undercontrol-of pistonv,

live air pass'age 15f of-limited size ex-. I ,tendsfrom branch 10 to passage15." i'

V ofaits working stroke. an" annular groove4 on the exter orthereof'servesxto effect':com- I 1 munication between port 10 and theaxially part of a longitudinally .disposed passage 17 V Piston 4'also controls the'main exhaust ports 18 and lQleading'direct to'atmosphere. 1

the {supply passage 10 through loranchlO V around. the neck 11 of the v'alveand through passage 14 to the. rear end ofxthe piston chamber; Y'Tli'efront jend of the'pistoncha'mi the piston advances it closes exhaust- 19 whereupon the airjtrapped in the forward end of the piston chamber is forced back into passage 17*. An instant later. the groove" 4 1 in the piston effects communication between the cross ports 10 and 16 whereupon passage 16,. is filled. with motive fluidfrom Ibranoh r 10". This primingjof passage 16 maybe as= sisted, if desired, loy'a constantly open live air port 201 of limite dsize communicating the piston 4 the rear endofthe' piston 0118,1111

her is openedto exhaust through port 18] producing an -immediate fall inpressure'g with branch 10?. .On further, movement. of-

uponpassage 17 is immediately filled with motive fluid from branch 10', which motive fluid is promptly effective through port 17 b V in starting pistons rearwardly'and also in throwing tl' evalvetoits rearmost position (F 1 g. 2). The movement or" the 'valve' establishes fcon' munication between passages 16 and 17 and the motive fluid heretofore trapped in passage l6,immediately becomes available to assist in the rearward movement -.o.l?'.p1ston-4l. -At the be inning otthe rear- 'Will'Cl stroke' ot the piston port .17 is prompt- Ply closedbut live air still passes to passagel6,;t-henee to passage 1'4 andthence to the forward end of the piston chamber until the cross ports 16 and 10 are closed. The piston then continues its rearward movement by mentum' the pressure rapidly in the forward end of the piston chamber but there expansion-oi the motiveffiuid at its forward end until exhaust port 19 is uncovered. its the pistoncontinues its movement by meisstillsuilicient pressure inpassages 16 and 17 to-maintainthe valve" in its rearward position, particularly since the rear end or the piston chamber is open, to exhaust through passage 14, valve chamber 12 and eXl1aust..p'or-t,13.. The piston then closes the endot passage .15 and thelive motive fluid-admitted. through restricted port l prompely builds up and becomes effective to shiftthe valve baclr toits original position shown in Fig. 1 'as the piston uncovers port 1'9 thus venting passages 17. and 1'6 and reof the piston .ca-i

0 I I 4 arestricted live air port 21 1s provided in,

lieving the pressure on the. forward end vof the valve. .'lhis"conipletes the cycle. v

.To prevent adelay in the forward shifting of the valve: in the-e vent that the momentum es it rearwardly suiiicient into register with port 15,

to bring groove communication with branch and disposed slightly. in advance of passage lS to prime the'groove' l anc prevent an undesired drop in pressure. in passage .Port 2,1 also serves .to'. assist port. 15% in building up I pressure. in passage .15 when the piston has stopped or is at restjintherear .end of the-piston chamber. The piston. is pref erably hollowed out. as indicated at 4 on its'irearward. endto lighten its weight and toaincrease the volume of therear end of the-piston.chamber. This is found to increase the speed of the piston and the power of the blow. V

' From-the aboveflitnvill be apparent that the .;present inven i nsets forth [a tool 01" simple. and rugged. c ristruction,economical in the consumption of motive fluid, and developingthe maximum of power from the motive fluid used. Although the'pretered form of the invention has been herein shown and'described it is to be understoodthat the-invention isnot confined to tlie'specific details thereof, but covers'allchan'ges, modi-- tive fluid supply on movement of the 7 '111 one direction but-to continuo the admisfications and adaptations within] the scope end of the piston Jchainberaiter said; first named means becomes inoperat ve.

2. In a fluid ressure. percussive tool, cylinder providing a piston charhberja piston reciprocable therein, asvalve-moving 1n timed v relation with the movements of said piston,

means controlled by said valve: for supplying chain means i'notivetiuidto oneend of the piston her,independent motive fluid supply controlled by said piston or the other end of I the piston. chan controlled Lineans tor: prolonging-the supply I U51", and piston and valve otmotive fluid to the last named end of the piston chamber after said second named meansbecomes inoperative.

3. Ina fluid pressure percussive tool, acylind-er providing a piston chamber, a piston reciprocable-therein a valve controlling the' 1. In a fluid pressure percussive tool, a

supply of motive fiuid toone endoi the piston chamber and means controlled by said piston for directinginotive fluid to the other end of the piston chamber,saidmeans coniprising longitudinally spaced ports in the cylinder wall leading to the front end of the piston chamberand to the valve respectively and a groove-in the piston arranged to connect said ports with the motivefluid supply.

. l. In fluid pressure percussive tool, a"

cylinder pro viding a piston chamber,-agpis ton reciproca-ble therein, a valvejcontrolhng the supply otinotive'fluid to one'end-ot-the piston chamber, and-means controlled by said,

piston ior direc ng motivetlui'd to the other end ofthe piston chamber;comprising pi sages having long udinallyspaced ports in the cylinder wall,

groove in tlie'jpistonar rangedto s'pansaid' ports and oonnectthe samewiththe motive fluid supply, said ports and passagesl so arranged asto direct motive fluid-to the end or the piston chamber when the second port is connected to the mosionuntil the firstiportis closed by the piston on itsreverse movement. I i In a fluidpressure percussive tool, a cylinder providing a piston chamber, pistonreciprocable therein,a valve controlling the supplyof motive fluid-to on'eQendot the piston chamber, and means controlledfby said pistonctordirecting' motive fluid tothe other endozt the piston chamber, comprising-passages having longitudinally spaced-ports in Z 9 H the cylinder wall, a groove in the piston ar and a groove inthe piston chamber arranged ranged to span said portsand connect the same with the motive fluid supply, said ports sion untilfthe first port is closed by the piston 0n itsreverse movement," one of said passages being under controlot saidvalve'.

6.-In a' fluid; pressure percussive moracylinder providing a piston chamber, a pis iton reclproca-ble therein controlling a mam exhaust port, a valve controlling the, supply of motive fluid to one end'of the piston chamber, and means controlled by said pis-- ton for directing motive fluid tothe other end of the piston chambercomprising 1on4 gitudinally spaced ports in the cylinder wall to connect said ports with the motivefluid supply,said piston being arranged to :pass beyond one of said ports to open the same to said main exhaust.

7 In a fluid pressure percussive tool, a cylinder provldlng a piston chamber, a piston reciprocable therein, having an annular groove, a valve controlhng'the supply of motive fluid to, one end'of the piston chamber, a live air passage insaid cylinder havt ing a port opening into the piston chamber,

and means controlled bysaid piston for'di- 'recting motivefluidto the other end'of the piston chamber, said means comprising independent passageshaving ports opening in V M .by a built up pressure including avent port 1 tosaid piston chamber so positioned as to be connected to said live lair port by said t groove 1n the piston, said lastnamed pas-' sages being also arranged to be lnterconnect ed by said valve, and meansfor primingone of said last named passages prlor to the con- 7 nection of the other to the motive fluid supply by said piston. i o v I ,8. In a fluid pressure percussive tool', ,a

' ed to said'live air po -thy said groove-in the cylinder providing av piston chamber, pisi= ton reciprocable therein, having an annular groove, a valve, controlling the supply or mo-,

tivefluid to one end of the piston chamber,

a live air passage in said cylinder having aport opening into the piston chamber, and

means controlled by said piston for directing motive fluid to the other end'of the piston chamber,sa'id means comprising indepen'dent passages having ports OPG IIlIIg IIItO said piston chamber so disposed as to be connectpiston, said last named passages being also arranged to be lnterconnected by sald valve,

I and a live air port continuously admitting-i f'. last named passages.

: motive fluid. in limited amount to one of said 9. In a-fluid'pressur'e operated tool, a cyl I tinder providing a piston chamber,a piston reciprocable therein,1a valve controlling the ton chamber, a passage extending to theopsupply of motive fluid toone end of the pisposite end ofthe piston chamber and to a pressure area of thefvalve, means controlled 7, by saidpiston "for admitting motive fluid to sa d passage,-and a second passage arranged to form a motive fluid storage chamber of substantial size and to-be filled with motive V fluid, said second passage being connected to said first passage upon shifting of the valve;-

.10, In a fluid pressure operated tool, a

cylinder providing apiston. chamber,a' pis tOIl-TGCIPIQCiLblG therein,.a valve controlling f piston chamber, a passage extending to the oppos1te'end of the "piston chamber and to a it-hesupply of motive fluid to one enol'of the I pressure area of the valve, means controlled i by said.v piston for admitting motive fluidto SH-1d passage, and a second passage'also unbe filled with motive fluid in advance of said 'firstnamcd passage to provide a motive fluid der control of said piston and arranged to storage chamber of substantial size, said sec- 7 ond passage being connected to said first pas sage by said-valve on shifting of the same."

11. In afluid inder providing reoiprocable' therein, a controlling valve therefor moving in timed relation-With the piston, said piston havingfa recess in the exterior thereof, means for shitting said valve under controlof said piston, and {means pre 7 pressure operated tool, a cyla PlSljOli chamber, a piston venting saidrecess from interfering'with the; I

control of said "valve, by saidpistona v '12. In a fluid pressure operated tool, a.

cylinder providing-a piston chamber, a piston j I 'reciprocable therein, aycontrolling valve therefor moving in timed relation with the piston,'said piston having-a recess in the" exteriorthereof, means admitting motive fluidfcontmuouslyfm limited amount to a pres-2' sure area ofsaid valve, a vent passage extending from said areato the piston chamber 1 to beclosed'by said piston to cause the continuously admitted motive fluid to build up 1 'ERNESTVPENBERTHYL pressure against said area of the valve, and

motive fluid to 'insureaccurately timed shift 

